I might counter, Dave, by saying that, as a PhD in Unsteady Aerodynamics, who has worked for Airbus, QinetiQ+NASA, FTE @ Boscombe Down (albeit as a contractor working on the JSF) amongst others, I'm quite happy to believe my own conclusions about what deposits do to airflow, the difference being that I'm quite sure the Navier Stokes are fairly complicated last time I looked and they often yield odd solutions, if indeed you can solve them in the first place.
When I did my PhD I used to leave simulations running for days and days (not enough computing power on the University servers) to yield a solution and I was "only" using nonlinear indicial responses as opposed to full CFD.
Granted it was F/A-18 aerodynamics not the internal combustion engine...so we're talking about $50 million dollar products not $55K ones so the value of small margins of "extra performance" is that much more important....still I digress and it was a long time ago...
The debate has lost a degree of lustre I agree...
But I'm curious...
Would you object then if a manufacturer managed to build a DI engine that didn't deposit so much carbon in its manifold?
That'd be presumably a waste of time would it?
I don't understand why anyone would not consider such an engine a better product?
Thats what we're talking about.
Prior to DI, it was never acceptable to have that kind of material "floating" around in an engine that close to some expensive moving parts...
Why now?
People can make their own mind up about the performance delta. In fact I think there is even consensus on that....1-2% perhaps? Maybe even a bit more?
I wonder if the Veyron suffers?
